3-Quinolinecarboxamide derivatives are described in U.S. Pat. Nos. 4,547,511, 6,077,851, 6,133,285 and 6,121,287. The term “3-quinolinecarboxamide derivative” as used in this specification designates the undissociated acid form, hereinafter called the neutral form, of the compound of formula (I), i.e., the form as given in the formula (I).

It was unexpectedly found that some 3-quinolinecarboxamide derivatives in the neutral form disclosed in the above US patents are susceptible to chemical degradation in solid state, and, in particular, when in pharmaceutical formulations. Some salts of the 3-quinoline-carboxamide derivatives of formula (I) are known from said US patents. However, none of the above-mentioned patent specifications discloses an enabling method of providing 3-quinoline-carboxamide derivatives of formula (I) susceptible to degradation in a sufficiently stable pharmaceutical form or even suggests any particular advantage of using the salt form of a 3-quinolinecarboxamide derivative in pharmaceutical formulations.